1. Field
The features described below relate generally to reducing delays in acquiring service for a mobile equipment (ME). Examples of ME may include, but are not limited to, a cell phone, smart phone, tablet computer, laptop or other portable devices. More specifically, various embodiments are directed to optimization systems and methods that prioritize access to a SIM (Subscriber Identity Module) to reduce delays in acquiring services from a network. Services include but are not limited to voice, data, GPS, or text.
2. Background
A Subscriber Identity Module (SIM), such as but not limited to, a Removable User Identity Module (R-UIM), CDMA Subscriber Identity Module (CSIM), Universal Subscriber Identity Module (USIM), or GSM SIM, contains information relating to a user of a ME. A typical ME may take the form of, but is not limited to, a cellular radiotelephone, satellite radiotelephone, a PCMCIA card incorporated within a computer, a PDA equipped with wireless communication capabilities, a smart phone, a tablet computer or the like.
A SIM typically includes a controller and memory housed in a card-like structure. The memory may contain user information including, for example, a subscriber/user identifier, a phonebook providing a stored bank of telephone numbers, messages, billing codes, encryption sequences for secure wireless data communication, and other useful information that can be retrieved during the use of the ME. The memory also may store applications that are accessed by the ME, e.g., for over-the-air service provisioning, cryptography, web browsing, or mobile commerce.
A SIM includes a relatively simple electrical interface, including an input/output (I/O) port for exchanging serial data with another device such as an ME, a clock input for receiving an external clock signal, and a reset input for receiving a reset signal. A SIM receives power from the device in which it is installed.
All requests to a SIM are queued by the software controlling the SIM because the SIM processes only one request at a time. The requests to the SIM are sent in a queue and are processed using a “first in, first out” (FIFO) algorithm. The ISO interface used to communicate with the SIM can be slower (e.g. milliseconds) than the processing speeds of most MEs (e.g. microseconds or nanoseconds). Accordingly, the SIM may introduce delays while processing the requests. Access to data needed for registration and/or authentication requests directed to the SIM may wait for other modules that may be accessing the SIM with other types of requests. The delays caused by the other modules and the FIFO queue may prevent the ME from registering and initiating a phone call.
Multiple network access applications may be initialized one after another on one SIM and each application being used to register with a different network, such as but not limited to, UICC (Universal IC cards) cards with USIM (Universal Subscriber Identification Module) and CSIM (CDMA Subscriber Identity Module) to acquire LTE and 1× networks. New SIM cards with multiple network access applications have a larger number of files than the number of files in the SIM cards of the past. UICC cards with multiple applications can introduce additional delays. For example, if the applications are initialized in sequence, such as, the request for a first initialized application is received before the second application is initialized, the first initialized application may request data which may create a long queue of operations. The delay in registering the ME to the network with the 2nd application can be long. Various embodiments are directed to optimization systems and methods that prioritize access to a SIM in ME to reduce service acquisition delays.